The death of the 48-year-old Grammy award-winning star, who was one of the world's bestselling artists in the 1980s and 1990s, was confirmed by her publicist, leaving the entertainment industry and fans around the world in shock.

Detectives said paramedics unsuccessfully tried to resuscitate the singer, who was pronounced dead at 3.55pm local time.

Houston was due to appear at the LA gala of music's biggest occasion – the Grammy Awards – later tonight and had also been at rehearsals for the show, coaching singers Brandy and Monica.

It is believed she had been due to perform at the annual pre-Grammy party of her long-time mentor, record producer Clive Davis, at the Beverly Hilton, but was found hours before it began.

Police said there were no "obvious signs" of any criminal intent in relation to Houston's death.

Lieutenant Mark Rosen, from Beverly Hills Police, told the BBC the star was pronounced dead at the hotel.

He said her family had been informed and the matter would be passed to the coroner following the police probe.

Organisers of the Grammys have said Houston will be remembered at tonight's awards in a tribute by Jennifer Hudson.

Following the news, fellow celebrities and contemporaries lined up to pay their respects, with describing the star as a "legend" and an "icon".

Mariah Carey, who recorded the duet When You Believe with Houston in 1998, said she was "heartbroken".

"Heartbroken and in tears over the shocking death of my friend, the incomparable Ms. Whitney Houston," she wrote on Twitter.

"My heartfelt condolences to Whitney's family and to all her millions of fans throughout the world.

"She will never be forgotten as one of the greatest voices to ever grace the earth."

Music mogul Simon Cowell described Houston as "one of the greatest singers of all time", and said he expected tonight's Grammys to become a tribute to the "trailblazer" and "legend".

He told Heart FM: " ... you have to remember a lot of the people who are going to be getting awards at the Grammys, they owe an awful lot of their success, I believe, to Whitney, because Whitney was a trailblazer. It's a night she deserves to be remembered fondly."

Houston appeared on the X Factor in Britain in 2009 following an invite from Cowell.

"We all knew that she had issues and I last met her when she came on X Factor in England when she was doing her comeback album and you could sense at the time there were a still few problems, but she was a delight to work with on the day, she was very professional, she was kind to everyone around her, she probably wasn't altogether there, but it was still Whitney Houston and you know that you are in a presence of a legend and I will never forget that day."

"There are so few people like her in the world. They are a rarefied breed, these are true superstar, legendary divas and I say divas in the nicest possible way. She had one of the greatest voices I have ever heard in my life, ever."

Cowell told CNN Houston was the benchmark that contestants on his reality shows had always tried to reach, and revealed he was going to discuss the possibility of the late singer potentially joining the judging panel of the American X Factor with producers next week.

Mitch Winehouse, father of late British singer Amy Winehouse who died last year, paid tribute to Houston and the recently deceased Etta James on the social networking site, writing: "Amy, Etta, Whitney.

Their music will never die. What a great girl group in heaven."

Houston won multiple Grammys including album and record of the year, selling millions of albums and singles worldwide.

The I Will Always Love You and Saving All My Love singer also carried her success into the film industry, appearing in hit movies including The Bodyguard.

But her career began to unravel as she battled with drug addiction, spending various spells in rehab. Her powerful voice began to suffer, prompting record sales to nosedive and in 2007 her 15-year marriage to husband Bobby Brown came to an end.

Brown, also a singer, told a sell-out crowd in Mississippi: "First of all, I want to tell you that I love you all. Second, I would like to say, I love you Whitney. The hardest thing for me to do is to come on this stage."

Last week Houston was pictured looking dishevelled and disorientated as she left a Hollywood nightclub with her daughter Bobbi Kristina after performing at a pre-Grammy party.

The soul star, who some speculated was on the brink of bankruptcy, had made a comeback in 2009 releasing a new album after seven years off the scene.

In a tribute on Twitter, her godmother Aretha Franklin said: "I just can't talk about it now, It's so stunning and unbelievable. I couldn't believe what I was reading coming across the TV screen. My heart goes out to Cissy, her daughter Bobby Kris, her family and Bobby."

In a statement, country singer Dolly Parton said: "Mine is only one of millions of hearts broken over the death of Whitney Houston.

"I will always be grateful and in awe of the wonderful performance she did on my song and I can truly say from the bottom of my heart, "Whitney, I will always love you. You will be missed."